Mladen Mejovšek

Dynamics stability in landing with ACL deficient knee joint

The purpose of this research was to determine the effect of the controlled landing tests in dynamics stabilities of ACL deficient knee pre- and post reconstruction. The test protocol included experimental and control groups. The experimental group included examines with ACL deficient knee while control group consisted of healthy examines. The protocol consisted of following testing phases: 1. testing of the knee joint muscle power (execution of the maximum voluntary contraction during which the myoelectric signals were collected) and 2. testing of the knee joint dynamic stability (execution of the test with one-legged (landings) from the 40 cm and 20 cm high bench, during which the kinematic and kinetic parameters were collected). Following variables were studied: kinematic (valgus and varus, inner and outer rotation and angle of the flexion and extension in the knee joint), ground reaction force and EMG signals of the four main muscle of lower extremity have been measured during execution of the maximum static contraction lasting for 10 seconds. The protocol consisted of two testing period time pre- and post reconstruction of ACL. Statistically significant difference between groups in the first measurement as well as between injured and healthy knee was observed. That was the case especially in kinematical parameters (in inner and outer rotation angle as well as valgus-varus movement). Generally, a change in landing dynamics of the injured knee was observed. The differences are reduced following the reconstruction, and that is especially the case in examinees that underwent proprioceptive treatment during rehabilitation. The test could be applicable as an indicator of readiness of athletes to sustain training workload as well as a predictor of injury occurrence in healthy people.

NEW LABORATORY TEST FOR DYNAMIC STABILITY IN ACL DEFICIENT KNEE JOINT

Anterior cruciate ligament (ACL) injuries are common in sports. Knee injuries are the most common, and have the greatest potential to cause both short term and long term disability. Dynamic stability of the knee during such activities is determined by the balance of muscle strength, lower extremity muscle fatigue, ligament function, joint structures contact, and ground reaction forces applied to the leg. The purpose of this research was to determine the effect of the controlled landing tests in dynamic stability. Optoelectronic system BTS ELITE, offering integration of kinematics data with the external signals of force platforms and EMG devices, was used for experiments. The developed test protocol could be applicable as an indicator of readiness of athletes to sustain training workload as well as a predictor of injury occurrence in healthy people.